382 



BULLETIN OF THE BUREAU OF FISHERIES. 



Plumularia inermis Nutting. 



. Plumularia inermis Nutting, American Hydroids, pt. I, 1900. p. 6r. 



Trophosome. — Colony simple, unbranched, reaching the height of about half an inch; divided into 

 regular, long, slender intemodes, each of which bears a hydrocladium from a process at its distal end. 



The hydrocladia are divided into regular intemodes, 

 T all of which, including the proximal, bear hydrothecse, 



except very occasionally when there may be an inter- 

 mediate intcmode. These intemodes are long and 

 slender, so that there is a long interval between two 

 successive hydrothecae. Hydrothecse shallow cam- 

 panulate; supracalycine nematophores are absent. 

 There is a nematophore above and one below the 

 hydrotheca and one at the axil of each hydrocladium; 

 hydranths too large to be entirely retracted into the 

 hj'drotheCEe. 



Gonosome .^Unkno«-n . 



Distribution. — On Turbinaria off Bogue Bank. 



Plumularia setaceoides Bale. 



Plumularia setaceoides Bale, Hydroida of Soutlieastern Aus- 

 tralia, iSSi, p. 28. 



Tropho.sorae. — Colony, in Beaufort specimens, not 

 more than i inch in height, but Bale reports them up 

 to 3 inches; sim.ple, unbranched, divided into regular 

 intemodes, each giving off a hydrocladium from a 

 process near the distal end; two or even three or four 

 annulations at each node; hydrocladia slender, re- 

 curved, with alternating nonliydrothecate and hydro- 

 thecate intemodes, the proximal being nonhydrothe- 



cate. This and all the intermediate intemodes have two internal ridges. The hydrothecate intemodes 



have one or two ridges proximal to the hydrotheca and one opposite the base of the hydrotheca. 



Hydrothecae cup-shaped, with about one-third of 



the distal end free; supracalycine nematophores 



present, one nematophore below the hydrotheca, 



one on each intermediate intemode but none on 



the proximal. one in the axilof each hydrocladium 



and one on each intemode of the stem. 



Gonosome. — Gonangia very large for such a 



slender colony, borne on the face of tiie stem, at 



the base of the hydrocladium. Bale reports them 



as sometimes forming two rows reaching halfway 



up the stem, but I found them singly only. They 



are oblong in shape but are curved so that the 



convex lower surface is much longer than the 



concave upper surface, and the whole gonangium 



projects outward almost at right angles to the p,a. si-Plumularia setaceoides Ba\e. A, poffion o! colony with 



stem. Proximally it tapers gradually to the gonangium; B, hydrocladium, more highly magnified. 



point of attachment, distally it is truncate. 



There are several distinct, though not very deep corrugations. 



Distribution. — On floating Sargassum and Turbinaria off Bogue Bank. 



Fig. so- — Plumularia inermis Nutting. 



